Class Notes (839,394)
Canada (511,324)
Biology (6,826)
Lecture

Lectures 17 - 24 Notes

26 Pages
158 Views

Department
Biology
Course Code
Biology 2217B
Professor
Richard Gardiner

This preview shows pages 1,2,3,4. Sign up to view the full 26 pages of the document.
Description
Lecture 17: Herbs and Spices Herbs and Spices  What’s the difference? o Interchangeable terms o Herbs – usually leaves or seeds from temperate-origin plants o Spices – usually aromatic or pungent flowers, fruits, or bark of tropical-origin plants o Both add flavoring to food  Spices: o Aromatic and pungent products of tropical plants o Properties based on essential oils – benzene or terpene derivatives  Herbs: o Small temperate plants used for aromatic constituents  Incenses: o Plant substances that release fragrances when burned  Scents and flavors usually use to unique “essential oils” o Secondary compounds, especially isoprenoids (terpenes)  Natural plant function in pollinator and fruit/seed-dispenser attraction  Plant protection from herbivores and pathogens (mostly fungi, bacteria)  Most of these secondary compounds have anti-microbial activities  Herbs are more easily categorized – see table 17.3  Spices have no main families – see table 17.1  Many spices are tropical, and are rare or absent from our temperate part of the world Spice  Derives from the Latin word species, meaning specific kind, and later, goods or merchandise  Early significance o Magical rites and spells o Purification ceremonies and embalming o Fragrances and perfumes o Flavoring and condiments o Food preservation o Curatives, aphrodisiacs, vermifuges o Poisons  Valued commodity, sometimes used as currency  Rome once held ransom for precious metals and 3000 pounds of pepper  Early explorers, Columbus, Megellan, and Ferdinand risked lives to discover faster routes to spice-producing countries Spice Influence: Findings 1. Hypothesis – spices enhance the flavor of food Support – spices do, in fact, enhance flavor Argument – leaves many unanswered questions o Why do we like them? What causes cultural preferences? 2. Hypothesis – spices mask the smell of spoiled foods Support – mixed with spices, spoiled foods are more palatable Argument – masking spoiled foods has major drawbacks 3. Hypothesis – exotic spices serve as a symbol of wealth Support – rare species could only be enjoyed by the affluent Argument – spices are used most prominently in the areas they naturally flourish 4. Hypothesis – spices cool the body by inducing perspiration Support – some spices increase sweating, would help people stay cool in hot climates Argument – most spices don’t increase perspiration, other mechanisms control homeostasis 5. Hypothesis – spices are used as medicaments Support – spices have pharmacological uses in many cultures Argument – spices are used in staple foods 6. Hypothesis – spices are used to preserve foods Support – antimicrobial effects of spices could serve as palatable and efficient way to preserve food Recipes and Spices  The average meat recipe calls for 3.9 spices  93% of all recipes called for at least one spice  Number of spices used in recipes range from 0 to 12 Early Spices  Old world/ Orient o Cinnamon, nutmeg, mace, black pepper, ginger, cloves, cardamom, anise, caraway, mustard, saffron  New world o Allspice, chilies, paprika, vanilla Taste, Odor, and Flavor  Taste o Sensations experienced by the chemoreceptors in taste buds on the tongue, soft palate, pharynx and epiglottis  Odor o Volatile chemical sensations experienced by the olfactory glands in the nasal cavity  Flavor o Experienced when we eat or drink o Composed of the sensations of taste, odor, and (to some extent) temperature and physical or chemical irritation Tastes  Sweet – sugars, some proteins  Salty – NaCl, Li, K  Sour – acidic, H+ ion channels  Bitter – quinine (club soda)  Umami (savory) – amino acids, MSG  Piquance – chili peppers, capsaicin  Cool – minty (trigeminal nerves)  Dry – astringent (tannins), nerves sense drying of the mucous coating of the mouth, perhaps also denaturation of proteins  Temperature – impressions that greatly affect how we experience food or drink Odors  Any flavor beyond those listed above is experienced through the olfactory glands is the nasal cavity  We call these chemicals in food “aromatic” because they are volatile and give aroma o Many of these chemicals are also what chemists would call aromatic compounds Terpenes  Many varieties, based on the isoprene molecule 5 8 (rubber)  Secondary metabolites  Act as anti-herbivory and anti-infection compounds in plants, thus often concentrated in otherwise tasty leaves, flowers and fruits Alliaceae  Allium o cepa – onions o sativum – garlic o porrum – leeks o schoenoprasum – chives  Flavor and scent due to sulphur compounds o After eating, transported to lungs for disposal  Onions and garlic have been cultivated for a long time o Culinary and medicinal reasons  Sulphur compounds inhibit many bacteria and fungi Black Pepper  Piper nigrum o Magnoliopsida  Cultivated for fruit o Drupe (5 mm dia.) o Black, white, and green  Piperine o Alkaloid responsible for pungency  Can be stored in air tight container for many years  India, Indonesia, Malaysia, Sri Lanka, Vietnam, Brazil are major producers  Most widely traded spice – 35% of spice trade  Pain relief, rheumatism, flu, colds, muscular aches  Canned green pepper, whole black pepper, whole white pepper  Climbing vine native to India and East Indies o Piperaceae (pepper) family  Berries picked green, darken and shrivel upon drying  Biting flavor due to violate oils o Flavor dissipates after grinding  White pepper – berries ripen on vine, outer hull removed Clove  Syzgium aromaticum o Magnoliopsida o Ancient and valuable spices of Orient  Medium-sized tree  Dried, unopened flower buds o Buds resemble nails  Indonesia – world’s largest producer  Best used whole, because flavor deteriorates quickly once powdered  Used extensively in India  Oil of clove (eugenol) used for flavoring  Medicine – antibacterial, antiseptic, toothaches  Perfumes, soaps and cleaning products  Clearing agent for histological work  Parts used – closed flower buds  Active compounds – clove oil is 60-90% eugenol, which is the source of it anesthetic and antiseptic properties  An evergreen tree, 15-30 feet tall o In Myrtaceae (Myrtle) family  Native to the Spice Islands and the Philippines, but also grown in other tropical areas Ginger  Zingiber officinale  Common in many foods and beverages  Rhizome processed into fresh paste, dried powder, and preserved slices  Medical o Anticancer, anti-inflammatory, antioxidant, anti-ulcer o One of the most widely and extensively used spices o Treats stomach upset, diarrhea and nausea  Large producers o China, India, Nigeria, Thailand o Can be grown in N. America  Perennial native to tropical Asia  Name from Sanskrit word stringa-vera, which means “with a body like a horn”  19 century English pub owners put out small containers of ground ginger, for people to sprinkle into their beer o The origin of ginger ale Turmeric  Curcuma longa  Member of ginger family  Perennial native to tropical Asia  Like ginger, rhizome is used  Culinary uses in Eastern Hemisphere  Also used for dye Saffron  Crocus sativus o Iris family  Most expensive spice  From ‘zafaran’ in Arabic  Used as a yellow dye  Propagated by corms  Stigmas are removed from flowers and dried  From 3-parted stigma of monocot flower  Dried by slow-roasting  Imparts delicate and distinct taste and color  Used in French, Spanish, Middle Eastern and Indian cooking  Each saffron crocus flower has 3 stigmas o Ca. 80,000 flowers (240,000) stigmas to make 1lb of saffron o Twelve days to pick o Cost: >$250 oz. o 1400s: any merchant caught selling adulterated saffron in Bavaria was burned alive Vanilla  Vanilla planifolia  Perennial monocot vine  Native to central America and Mexico  Elongated fruits or capsules (called pods)  Picked green, slow process of drying, fermenting to give black pods  Behind saffron and cardamom, vanilla is 3rd most expensive spice  Unlike other “beans” vanilla is not a legume  Non-culinary uses include: Aromatizing perfumes, cigars, & liqueurs  Europeans prefer the bean, while N. Americans the extract  Extract made by percolating alcohol & water through chopped cured beans  Flavouring comes from the seed pod, or the ‘bean’ of the vanilla plant  Member of orchid family (Orchidaceae) – perennial vine Nutmeg and Mace  Myristica fragans  Part used – dried kernel of the seed  Tree grows ~25ft high, has a greyish-brown smooth bark,abounding in a yellow juice.  Myristicaceae (nutmeg) family  Dicot, native to Spice Islands;  Fruit is source of both nutmeg and mace  Mace is derived from the net-like aril that is wrapped around the pit.  Within the pit is a single seed o The source of nutmeg  Hallucinogenic in large amounts Star Anise  Illicium verum o Closely resembles anise in flavor  From star-shaped fruit, harvested before ripe and sun dried  Small tree, native to China and Vietnam  Oil used to flavor liquorice, cakes and biscuits  Available whole or ground  Confectionaries  Meat and poultry dishes  Potent antimicrobial properties  Antioxidant  Insecticidal property- German cockroaches Allspice  Pimerta dioica  Dicot  Jamaica pepper or newspice  Dried unripe fruits  Combines flavour of cinnamon, nutmeg and cloves – (1621 by English)  Seeds must go through avian gut to germinate Lecture 18: Medicinal Plants Medicines from Plants  Over 120 distinct chemicals considered to be important dugs are widely used in countries around the world  Over 25% of common medicines contain some compounds obtained from plants.  In US approx. 10% of major drugs have plant extracts as their active ingredient.  In less developed countries WHO estimates that 75-80% of people rely on plant-based medicines for primary health care Definitions  Herbal medicines: “plant-derived” medicines, chemically unaltered from their pure, original form  Drug: “any chemical substance that, when absorbed into the body of a living organism, alters normal bodily function”; OR “a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being.”  Natural products: several categories or health care products that are found in nature, produced by living organisms Ginseng  Medicinal use of ginseng (Panax, Araliaceae) goes back at least 5000 years in China Doctrine of Signatures  Humans suffered from innumerable maladies and diseases – they experimented with plant cures.  The concept of the plant signature was conceived to help determine which plants were beneficial  Since plants were placed on earth for the good of mankind, the look and colour of a plant provided visual cues in the plant itself; its unique “signature”  Developed by Paracelsus and published during the first half of the 16 century. Paracelsus (1493 – 1591) traveled throughout Europe and to the Levant and Egypt, curing people and experimenting with new plants in search of more treatments and solutions o Yellow and sweet = spleen o Red and bitter = heart o Green and sour = liver o Black and salty = lungs  Hepatica nobilis derives its Latin name from its use, as a cure for liver disorders (e.g., hepatitis, jaundice).  Although no known benefits to the liver, it is used as a topical astringent or as a diuretic Foxglove  Digatilis purpurea, Scrophulariaceae, Plantaginaceae  Active compounds mostly extracted from leaves of the second year’s growth  In pure form, are referred to by common chemical names such as digitoxin or digoxin  Cardiac glycosides are used mainly in the treatment of heart failure o Inhibits sodium potassium pumps, buildup of sodium supplies Willow Bark  Bark of willows (Salix, Salicaceae) contain salicin o Close relative of acetylsalicyclic acid  Anti-inflammatory, antipyretic (fever-reducing) analgesic (pain-reducing), and anti-cyclo-oxygenase (blood clot reducer)  Hippocrates used will bark to treat pain  Bayer company (1897) synthesizes, and named it Aspirin Malaria  Mosquito bite o Carries Plasmodium, a parasitic protest of about 40 species  Infects red blood cells  Approx. 48 hour interval of re-infection causes fever and chills  Malaria is the world’s most prevalent disease – it kills 2-3 million people annually Aloe  Aloe vera – the burn plant, or medicine plant  Liliaceae (lily family)  Many synonyms – A. barbadensis, A. indica, A. perfoliata  Originally native to Africa  Soothes sunburns, rashes, skin ulers, eczema, athlete’s foot, poison ivy, ringworm and minor wounds  Acts as a laxative and lowers blood glucose  Large succulent sword shaped leaves  When lacerated, leaves produce a thick sap o Chrysophanic acid Ephedrine  Ephedra – extract of Ephedra Sinica o Gymnosperm  Ephedrine and pseudo-ephedrine still used in over-the-counter and prescription medicines  Used in treatment of asthma and hay fever as a decongestant o Relaxes bronchial muscles  Regulated drug following cases of abuse and adverse effects Chaulmoogra Oil  Hydnocarpus  Leprosy – bacterial disease  Chaulmoogra oil – first effective treatment  Oil from seed is active ingredient  Now replaced with antibiotics Madagascar Periwinkle and Pacific Yew  Two important plants in the fight against cancer  Madagascar Periwinkle (Cathanranthus roseus) o Source of the alkaloids vinicristine and vinblastine  Pacific Yew  Taxus brevifolia o Source of taxol  Both plants are endangered in the wild  Madagascar gets no revnue from vinicristine, etc. Taxol  Taxus brevifolia  Isolated from the bark of the Pacific Yew  Acts on microtubules during cell division  Trees became endangered  Now produced synthetically Others  St. John’s Wort o Hypericum perforatum o Long history as herbal medicine o Used to fight depression  Ginkgo o Gingko biloba  Single surviving species of an ancient genus o Used by Chinese herbalists o Fight memory loss Guest Lecture: Plant Biotechnology What is Biotechnology?  Science of altering the genetic pattern of plants in order to increase their value o Plant breeding: genetic changes are introduced in crops by using various crossing and selection methods o Plant transformation: desirable traits (i.e., genes) are specifically introduced into crops Genetic Manipulation of Plants – Why?  Some staple crops have undesirable characteristics: o Susceptibility to diseases, insects o Low tolerance to cold, drought, salinity  Selection for: o Resistance to diseases and insects o Tolerance to abiotic stress such as cold, drought, etc. Genetic Manipulation of Plants – How?  Changing one or more genes, either by mutating a gene and knocking it out, downregulating or upregulating its expression, or by inserting a new gene into the genome  All this can be done by traditional genetics through breeding and introgression of genes  However, breeding can take a very long time, several years to achieve one target. As well, breeding is limited to species that are compatible.  Modern biotechnology through plant transformation allows for a much faster and more precise genetic manipulation.  Plants can be genetically transformed in several ways: o The nuclear genome can be transformed  Agrobacterium - mediated transformation  Biolistic - mediated transformation o The chloroplast genome can be transformed  Biolistic-mediated transformation Genetic Alterations  Rapeseed o Erucic acid glucosinolates = unfit for human and animal consumption  Later called canola o Selective breeding for low erucic acid and low glucosinolates o It took several years and much innovation to develop canola Agrobacterium-Mediated Transformation  Only organism capable of interkingdom gene transfer (5 kingdoms: monera, protista, fungi, plant, animal)  Can be used to transform plants, fungi and some mammalian cells  Has a circular chromosome, a linear chromosome and a Ti plasmid  Crown gall disease is caused by agrobacterium T-DNA  Hormones for tumor formation o Auxin o Cytokinin  Opines: o Amino acid – sugar conjugates o C and N source for agrobacterium only, and not for any other microorganisms o Gives a selective advantage to agrobacterium  Ti plasmid was disarmed, and placed in binary vector system Binary Vector System  Disarmed Ti plasmid containing virulence (vir) genes, but lacking T-DNA region  The T-DNA region is present on a second plasmid, the binary vector Biolistic Transformation  Agrobacterium cannot infect and/or transform some crop species and organelle genomes o Monocots: rice, corn o Legumes: soybean o Chloroplast genome  Another method for transforming these crops is biolistics Chloroplast Transformation  Chloroplasts have a genome too  Why? o Chloroplasts express large amounts of foreign proteins  Copy number (high ploidy of plastome)  Absence of position effects (integration by targeted homologous recombination)  Lack of transgene silencing o Correct folding of complex proteins and other post-translational modifications o Maternal inheritance for biological containment of transgenes Transplastomic vs. Transgenic Plants  The chloroplast genome = the plastome  Plants with transformed plastome = transplastomic plants  As opposed to plants with transformed nuclear genome = transgenic plants Southern Blotting  Named after Edwin Southern  Method used in molecular biology for detecting restriction fragment length polymorphisms in DNA samples  In this case, it allows us to detect the integration of the transgene in the chloroplast genome Chloroplast Genome Transformation 1. Build the construct 2. Introduce the construct into tobacco plastids (biolistic) 3. Regenerate and selective positive clones 4. Subject the selected clones to additional two rounds of regeneration 5. Root the regenerated plants and analyze their plastome and recombinant protein production Regulatory Issues with GMOs (PNTs)  In wrestling with the regulation of PNTs, the key issues that the regulators are concerned with are: o Gene transfer – how best to minimize or avoid the movement of genes into crops and other plant species o Human and animal health risks – how best to ensure that the products of biotechnology do not represent a threat to human or animal health o Environmental risks – how best to ensure that biotechnology activities do not represent a threat to the existing natural environment o Food/Feed Segregation – how best to ensure that PNT stay out of shipments intended for food or feed use. What are the Risks? Biosafety Concerns  Biopharmaceutical products in plants are biologically active and effects of chronic exposure are unknown  Containment is therefore a significant consideration for the prevention of uncontrolled release of the gene or gene products into the food chain or the environment Plant Biotechnology Applications  Input traits vs. Output traits o Input traits benefit farmers and seed companies but do not benefit consumers, e.g. insect, disease, drought, cold resistance, all lead to better yields and better profitability o Output traits benefit the consumer as well, such as improved nutritional qualities, proteins for human disease, industrial proteins Input Trait: Insect Resistant Crops  Bt, or Bacillus thuringiensis, is a bacterium which produces a toxin that kills insects but is not harmful to humans. This toxin was used for many years as a foliar insecticide  Bt corn was first introduced in the mid-1990s and offered protection against rootworm and corn borer, which are pests that are damaging to corn  Bt corn offered an insecticide built in to the crop, and led to reduced amounts of applied insecticide in the US  To prevent the development of resistant insects, 5% refuge must be planted in place of a transgenic variety Output Traits  Nutraceuticals o Metabolic engineering – golden rice  Pharmaceuticals (molecular farming) o Antibodies – HIV antibodies o Vaccines – H1N1 influenza vaccine, E. coli o Cytokines – Interleukin-10 Metabolic Engineering  Vitamin A deficiency is common in countries which consume rice as the staple food (Asia, Africa, South America)  Vitamin A plays an essential role in vision, immune response, bone growth, embryonic development, and more  Symptoms of vitamin A deficiency o Night blindness o Irreversible blindness o Increase by 9-fold child mortality  127 million preschool children are vitamin A deficient  250,000 – 500,000 become blind every year  50% of these die within a year of losing their sight Molecular Farming  Plants as hosts for the production of bio-pharmaceuticals  Global market for biopharmaceuticals o Driven by their high potency and ability to attack targets beyond the reach of traditional small molecule drugs, biopharmaceuticals are expected to surpass sales worth US $167 billion by 2015 o Higher approval success rate than traditional small molecule drugs o Higher investments and longer development times o More expensive than traditional medications (>$100,000/year) o Recombinant proteins are the biggest class of biopharmaceuticals (>65% of the total global biopharmaceutical sales) How are Biopharmaceutical Recombinant Proteins Made?  E. coli – insulin (1982) – no post-translational modifications  Yeast – (GM-CSF for bone marrow transplantation, Hirudin for anticoagulation) - hyperglycosylation  Mammalian cells – CHO cells – EPO, interferons, antibodies etc… - expensive Recombinant Proteins in Plants  Plants can process a wide variety of proteins  Free from human pathogens  Renewable source of proteins, easy to scale-up  Low cost and require limited facilities FDA Approval of First Plant-Made Pharmaceutical – May 2012  December 1st 2009, Pfizer acquired rights to Protalix’s taliglucerase-for Gaucher disease made in carrot suspension cell  May 2012, FDA approved it for use in humans Case Study – Interleukin-10  Protein requires complex processing  Anti-inflammatory cytokine  Potential for treatment of intractable diseases o Inflammatory Bowel Disease (IBD) o Psoriasis, wound healing  IL-10 -/- mice develop symptoms similar to IBD  IL-10 cost = $428/5 micrograms, mouse trial would cost $100K  Hypothesis – oral administration of IL-10 for the treatment of inflammatory bowel disease  IL-10 is biologically active in a murine cell assay  Plants expressing IL-10 can alleviate symptoms in a mouse model of IBD  IL10 -/- mice were fed 20% or 30% tobacco expressing IL- 10 for 30 days, with ranitidine in drinking water Limitations of Protein Production in Stable Transgenic Plants  Speed of production o Transformation and regeneration of a population (40-100) o Screening and selection of high expressors o Process takes 6 months to 1 year  Accumulation levels o Low levels most of the time  Purification from plant extracts o Column chromatography is the most expensive step in plant-made protein production Recombinant Protein Production in Plants  Stable transgenic plants – traditional  Transient expression – recent o Allows speed and flexibility  Stable transplastomic plants – limited species o Allows for high levels of recombinant proteins Transient Expression by Agro-Infiltration  R&D speed o From cloning to expression in 2 weeks o “No” transgene positional effect  Biosafety o No need to generate transgenic plants  High yield o Highly efficient gene delivery of Agrobacterium combined with high expression capacity Application of Transient Expression  Screen of fungal enzymes by transient expression in N. benthamiana o Set of 79 A. niger enzymes (collaboration with Adrian Tsang and Justin Powlowski from Concordia University) o No data on:  Expression levels in plants  Activity when produced in plants  Effectiveness in cocktails for cell wall degradation Medicago’s ProficiaTM Technology  Vaccines for pandemic and seasonal influenza viruses (Avian H5N1 and pandemic H1N1)  Agro-infiltration of N. bethamiana  Promoter and terminator of alfalfa plastocyanin gene  Co-expression of a suppressor of PTGS, P1/HcPro from PVY  Medicago Inc. o Aug 10, 2012 – awarded a $21 million grant from the Defense Advanced Research Projects Agency (DARPA), to demonstrate the scalable manufacturing of its plant-expressed VLP vaccines in the USA o July 24, 2012 – successfully completed the production of more than ten million doses of H1N1 VLP influenza vaccine in one month o Sept 25, 2012 – Medicago and Philip Morris Products signed a commercial agreement for production of Influenza Vaccines in China  However, transient expression is labor intensive and is economical for high value proteins  Another method to produce high levels of recombinant proteins is to produce transplastomic plants Summary  Transient expression helps in addressing speed and low accumulation problems in molecular farming, commercial facilities are set up and vaccines are in clinical trials  Chloroplast transformation can be used for high level production of simple proteins, feeding trials are planned for this year Lecture 21: Floriculture Victorian Sentiments  Victorian era was the period of Queen Victoria’s reign: 1837 – 1901  Long period of peace and prosperity in England – time of romanticism, mysticism, social values and the arts  Period of industrial and technological change Flowers  Long history of religious, folk, heraldic and national symbolism  Gifts of love, friendship and filial devotion o St. Valentine’s Day o Mothers’ Day Qualities of Ornamental Plants  Color – hue (combinations of blue, green and red perceived by eye), lightness or darkness of color, amount of color saturation  Texture – associate certain visual patterns with tactile sensations (i.e. velvety surfaces of leaves due to small leaf hairs)  Line – vertical branching patterns drive the eye up  Form – three dimensional quality Naming of Horticultural Plants  Can be given a Latin name  Hybrids get a formula name o Hybrid between Rosa alba and Rosa nigra would be written Rosa alba x R. nigra  Hybrids of unknown parentage o Rosa x wilsonii  Intergenic hybrids o xAster tuneri Floriculture  The cu
More Less
Unlock Document

Only pages 1,2,3,4 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit